To introduce the relevant characteristics of ANM EOS, lets first recall here a few definitions and terminologies.
The EOS of ANM at zero temperature can be described by the energy per nucleon (specific energy) \(E(\rho ,\delta )\) 
with \(\rho =\rho _{\mathrm {n}}+\rho _{\mathrm {p}}\)  being the nucleon density and \(\delta =(\rho _{\mathrm {n}}-\rho _{\mathrm {p}})/\rho \)  the isospin asymmetry of the system, here \(\rho _{\mathrm {n}}\)  and \(\rho _{\mathrm {p}}\)  are the neutron and proton densities, respectively. Preserving the neutron-proton exchange symmetry, it is usually expanded in even powers of \(\delta \)  as [1]}
\(E(\rho ,\delta )\approx E_0(\rho )+E_{\mathrm {sym}}(\rho )\delta ^2+E_{\mathrm {sym,4}}(\rho )\delta ^4+\cdots ,\) 
